Radiation therapy of squamous carcinoma of the tonsil: an analysis of prognostic factors and of treatment failures.

A retrospective analysis of the results of treatment by primary irradiation of 87 cases of squamous-cell carcinoma of the tonsil at one institution over a 20-year period is presented. Survival at 5 years for all patients was 20%. The major determinants of survival were tumour size (T) and nodal status (N) at presentation. Degree of histological differentiation had no prognostic significance. Initial failure occurred in the primary tonsil site or in cervical lymph nodes in almost all cases. It is clear that treatments that increase loco-regional control are needed if the prognosis for the more advanced tumours is to be improved and it is suggested that a combined-modality approach (surgery plus irradiation) needs to be explored. For early lesions, primary radiation therapy remains the treatment of choice.